Cut the tops off the artichokes and trim the leaves so that they will fit into a large covered pot. Fill a large pot with water so that the water comes midway up the artichokes. Add the olive oil, garlic salt and chipotle powder and bring to a boil over medium heat. Cook the artichokes in the boiling water, covered for approximately 30 minutes, starting with the base up, then turning once. The artichokes are done when a knife inserts easily into the base, and the leaves pull away with only a little resistance.
Add the marinade ingredients to a small bowl and stir to combine.
Heat grill to medium-high.
Remove the artichokes from the pot to a cutting board and let cool. Pour the marinade over the cut top of the artichokes and work the garlic gently into the leaves. You can cut and grill them immediately or leave them in the refrigerator overnight. When you are ready to grill, slice the artichokes lengthwise down the center and remove the choke. Put on a hot grill, and cook until they have good coloration on all sides. Transfer to a serving platter and serve with Chipotle Mayonnaise Dipping Sauce.
Combine all ingredients in a small bowl. The chipotle can be adjusted according to taste.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.